1. Field of the Invention
The present invention relates to a module connector structure, preferably but not necessarily in an optical module for performing optical communication, and in preferred embodiments more particularly relates to an SFP (Small Form Factor Pluggable) optical transceiver module whose housing is received within a cage of equipment to which the optical module is attached. The present invention also relates to a method for disconnecting such a module from a cage in which it is inserted.
2. Description of Related Art
Optical transceiver modules conventionally include a light emitting element and a light receiving element that perform photoelectric conversion to enable communication by optical fiber. Such optical transceiver modules include a housing designed to be detachably attached inside a cage mounted on a circuit board to which the module is connected. An electrical connector connected to the board is provided in the cage, so that a connecting terminal of the optical transceiver is constructed to be connected to the electric connector when the optical transceiver module is attached in the cage. The optical transceiver module thus constructed enables optical communication by converting an optical signal transmitted to and received from the optical fiber into an electric signal transmitted to and received from the board.
However, when the optical transceiver module is pulled out of the cage during operation of the optical transceiver module, there is not only the possibility that the communication is interrupted in progress, but also the possibility that the communication apparatus including the optical transceiver module is out of order. Therefore, the optical transceiver module needs to be reliably fixed to an inside of the cage at least during operation.
For example, in recent years, the standard of measure called MSA (Multi Source Agreement) of SFP (Small Form-factor Pluggable) transceivers is established to give compatibility to the optical transceivers provided by various companies, and the shapes and sizes of the SFP transceivers and the cages to which the SFP transceivers are attached are standardized. According to the MSA standard of the SFP, a protruding locking portion is provided at a bottom surface of an optical transceiver, and a cage is provided with a spring plate portion in which a locking recess (hole or depression) is formed in which the locking portion is locked.
Therefore, when the optical transceiver module is attached inside the cage, the locking portion of the optical transceiver module is locked in the locking hole of the cage, so that the optical transceiver module can be locked into the cage. On the other hand, it is necessary to release locking by detaching the locking portion from the locking hole of the spring plate portion by some means, when the optical transceiver module is removed from the cage.
As a conventional optical transceiver of this type, a construction including an ejector for releasing locking is disclosed in U.S. Pat. No. 6,434,015, the entirety of which is hereby expressly incorporated by reference.
FIG. 11 is a perspective view showing the conventional optical transceiver disclosed in U.S. Pat. No. 6,434,015 with its undersurface facing upward.
The conventional optical transceiver shown in FIG. 11 has a body 101 with a locking portion 114 formed thereon, which houses a light emitting element and a light receiving element, and an ejector 170 for removing the locking portion 114 from a locking hole (not shown) of the spring plate portion of a cage. The ejector 170 is housed inside an ejector seat which is formed at a lower portion 111 of the body 101, so that by pressing a pressing portion 179 provided at a rear end of the ejector 170, a tip end portion of the ejector 170 can be protruded to a vicinity of the locking portion 114 from an inside of the ejector seat. The tip end portion of the ejector 170 is designed to release the locked state of the locking portion 114 and the locking hole by bending the spring plate portion if it is projected when the locking portion 114 of the optical transceiver is locked in the locking hole of the spring plate portion of the cage.
Accordingly, this optical transceiver can removed from the inside of the cage by pressing a pressing portion 179 of the ejector 170 in the direction of the arrow g in the drawing to protrude the tip end portion to the vicinity of the locking portion 114, and releasing the locked state of the locking hole of the spring plate portion of the cage and the locking portion 114.
However, since the SFP optical transceiver according to the MSA standard is constructed to be about 10 mm high, and about 14 mm wide, and the module itself is compact, the ejector 170 (see FIG. 11) included in such an optical transceiver is a very small component. Therefore, the pressing portion 179 of the ejector 170 shown in FIG. 11 calls for a pushing operation with a fingertip or a nail in some housings. However, in the state in which the optical transceiver is attached in the cage, there is hardly a gap between the board on which the cage is loaded and the undersurface of the optical transceiver, and therefore a fingertip sometimes cannot successfully reach the pressing portion 179 of the ejector 170, thus causing the problem that the operation for releasing lock is difficult to perform.
The removing direction of the optical transceiver shown in FIG. 11 from the cage is the direction of the arrow h in FIG. 11, and this direction is the opposite direction from the pushing direction (the direction of the arrow g) of the ejector 170. Namely, in the conventional optical transceiver, the operating direction for releasing lock, and the operation direction for taking the optical transceiver from the cage are opposite to one another, and these operations have to be performed independently from each other. Therefore, the optical transceiver has the problem that the operation of releasing the lock to taking out the optical transceiver from the cage is troublesome.